Continuous absorption eefbig



Aug. 31, 1948. amus Re. 23,032

CONTINUOUS ABSORPTION REFRIGEHATING SYSTEM Original Filed Aug. 8, 1936 4 Sheets-Sheet 1 Aug. 31, 1948. c. c. Coons CONTINUOUS ABSORPTION REFRIGERATING SYSTEM 2 3 3 2 a v R Original Filed Aug.

4 Sheets-Sheet 2 II IIII Aug. 31, 1948. c. c. cooNs 23,032

I CONTINUOUS ABSORPTION REFRIGEBATING SYSTEM Original Filed Aug. 8, 1936 4 Sheets-Sheet 3' llllllllllll ai g 4, v ,8 I a 1 I i j5 9 5 7 1 II I I 50 l l 13 I v fl- 1948- c. c. cooNs 7 23,032

CONTINUOUS ABSORPTION REFRIGERATING SYSTEM Original Filed Aug. 8, 1936 4 Sheets-Sheet 4 Reissued Aug. 31, ms

CONTINUOUS ABSORPTION REFRIG- EBATING SYSTEM Curtis 0. Coons, North Canton, Ohio, aaaignor to The Hoover Company, North Canton, Ohio, a

corporation of Ohio Original No. 2,178,879, dated November I, 1939, Serial No. 94,984, August 9, 1936. Application for reissue January 10, 1941, Serial No. 813,970

15 Claims. (Chin-119.5)

1 This invention relates to continuous absorption refrigerating systems and more particularly to rectifiers and heat exchangers adapted to be used therein.

ating system, the heat ratio of the refrigerator is not high.

By means of the present invention. it is proposed to provide a continuous absorption refrig- .-erating system in which this heat of rectification is discharged into the strong aqua or'strong solution flowing from the absorber to the boiler, thereby improving the heat ratio.

It is preferable in accordance with the present invention to discharge the heat of rectification to the strong aqua instead of to the weak aqua due to the fact that the quantity of strong aquai'iowing is larger than the quantity of weak aqua by the amount of refrigerant absorbed in the absorber. Because of this it is not as practical to transfer .the heat of rectification to the weak aqua.

Accordingly it is one object of the present invention to efi'ect a savings 'of heat and to brin about an improvement in the heat ratio of a continuous absorption refrigerating s stem by transferring heat from the rectifier to the strong aqua flowing to the boiler.

It is still another object of the invention to provide an improved heat exchanger for transferring heat in the fluid leaving the boiler of a continuous absorption refrigerating system to fluid entering the boiler of that system.

It is still another object of the invention to provide an improved rectifier adapted for use in a continuous absorption refrigerating system.

In the following description. means is described for discharging heat of rectification to the stro aqua in the system. In all of the arrangements shown and described a single stage continuous absorption system using inert gas is illustrated but it is obvious that the rectifier and associated parts may be used in absorption systems which do not employ inert gas and also in systems in which two or more stages are employed. It will also be clear to those skilled in the art that the rectifier 2 of one of the following figures may other figures describedherein.

Various other objects and advantages reside in certain novel features of the arrangement and construction of parts as will be apparent from be used in the following description taken in connection with the accompanying drawings in which I Figure 1 is a diagram of a continuous absorption refrigerating system using inert gas and in which a rectifier constructed in accordance-with the present invention is illustrated in cross section. this arrangementshowing one embodiment of the invention.

Figure 2 is a diagram of a modified form of con-. tinuous absorption refrigerating systems and illustrating a further embodiment of the invention.

Figure 3 is a fragmentary. vertical cross sectional view of the rectifier of Figure 2 shown somewhat enlarged.

Figure 4 is a horizontal, cross sectional view of the rectifier shown in Figure 3, the view being takenon the line 4-4 thereof.

Figure 5 is a diagram of a continuous absorption refrigerating system illustrating still an-- other embodiment of the present invention and showing the rectifier and a portionof the analyaer of the system in vertical cross section.

Figure 6 is an enlarged fragmentary view in cross section of the rectifier assembly shown in Figure 5 Figure 7 is a horizontal crosssectional view of the rectifier assembly of Figure 6 taken on the line thereof. I

Figure 8 is a diagram of a continuous absorption refrigerating system illustrating still another embodiment of the invention and showing a horizontal rectifier in vertical cross section.

Figure 9 is an enlarged fragmentary vertical cross sectional view of the rectifier assembly shown in Figure 8.

Figure 19 is a transverse cross sectional view of the rectifier assembly shown in Figure 8, the view being taken on the line ill-iii thereof, and

Figure 11 is a transverse cross sectional view of the rectifier of Figure 8, the view being taken on the line I l-i i thereof.

Referring to the drawings in detail, and first to the arrangement diagrammatically illustrated in Figure 1, it will be seen that a continuous absorption refrigerating-system is there illustrated as consisting of a boiler B. a gas separation chamher 8, the rectifier designated generally at R, a condenser C, an evaporator E and an absorber A. these vessels being connected by a number of 2 conduitstoi'orm thecompietersiriaerating sys-.

from the boiler B into the gas separation chamber S. The refrigerant gas developed in the boiler system leaves the gas separation chamber- 8 through the conduit l2 and enters the bottom oi the rectifier proper. The rectifier consists of a vertically disposed cylinder it provided with a number or. baiiie platm l4 therein. The cylinder Isis surrounded by an outer jacket ll through which liquid may be circulated to remove heat from the interior of the cylinder is and from the bane plates ll therein to efiect' rectification as will presently be described more in detail.

The refrigerant gas leaves the top the rectifier is through the conduit it which conveys. it to the condenser C. Aiter the refrigerant condenses' in the condenser. it fiows into the evaporator through the conduit ll. The evaporator E is connected to the absorber A by means of two inertgas conduits is and II which may be in heat exchange relation. The conduit is may connect the bottom or the evaporator to the top oi the absorber and the conduit ll may connect the top of the evaporator to the bottom of the absorber.

The conduit is may have an inert gas circulator mounted therein as shown at I. and this circulator may be an ordinary centrifugal ian driven by a hermetically sealed electric motor Ii.

A liquid conduit 22 connects the bottom oi the gas separation chamber 8 to the top or the absorber. The bottom or the absorber is connected to the lower end or the Jacket II on the rectifier by means of the liquid conduit 23. The top oi. the jacket is is connected to a reservoir 24 by means of a liquid conduit 2! and the bottom or thereservoir as is connected to the boiler B by means 01' the liquid conduit ll.

proper operation or the system.

The rectifier itself is essentialiya heat exchanger and is part of the means tor transierring heat from the fluids leaving the boiler to the strong aqua iiowing to the boilerand it thus ,aidsintheeconomyoiheat.

It will be apparent that with this arrangement oi liquid conduits, liquid may flow by gravity from the gas separation chamber 8 through the con- I duit 22 into the top of the absorber and after trickling downwardly over baiiie plates or the like within the absorber, flow by, gravity through the conduit 2: upwardly through'the jacket I! and then downwardly through the liquid conduit 25 and the reservoir 24 back to the boiler through the conduit 20.

To prevent the accumulation of gas in the upper part of the jacket is a reversely bent pipe 21 may connect the top of theiacket to the re i'rigerant conduit it.

, The rectifier is must be provided with means for draining the liquid which collects therein. This .is provided by the liquid drain conduit II connecting the lower portion oi the conduit I! to the reservoir 2|.

It will be apparent from the above description that in the arrangement illustrated in Figure 1, the rectifier is located below the bottom of the absorber but above t e normal level or the solution in the reservoir 4. It will also be apparent that the strong aqua leaving the absorber through the conduit 23 is brought into heat exchange relation with the fluids in the rectifier is by means of the jacket i5. It'will also be clear that the pipes as and 22 may be in heat exchange relation and also that the pipe 28 which is connected to the bottom of the reservoir 24 may be in heat exb change relation with a. portion or the pipe 22. The relative amounts or heat exchange area between the pipes 22 and 23 as compared with the amount While the arrangement illustrated in Figure 1 shows bailie plates within the rectifier cylinder II. it is obvious that other filling material may be used.

The general ieatures oithe refrigerating systemshowninrigurslareknowntothose skilled in the art and-theoperation or the system as a whole need not be described here in detail. 2

A modified term of the invention is shown in Figure 2 of the drawings. The general arrangement of the assembly may be the same as in Figure 1 and the parts which correspond are similarly designated. The rectitler assembly is combined with the reservoir into a single cylindrical arrangement, the rectifier -|I occupying the upper portion thereof and consisting or a cylindrical vessel placed within the outer casing II. This is but a variation in details oi construction from the arrangement shown in Figure l. The reservoir It is vented through a conduit is which passes from the top of the reservoir to the conduit It. Another vent conduit ll connects the top or the jacket formed by the upper portion of the cylinder II to the upper end or the conduit ls.

An important ieature oi the arrangement of Figure 2 and one which differs from the arrangement of Figure 1, results from the fact that the absorption liquid leaving the absorber A through the conduit II is divided into two streams by means of a solution divider 32. The solution divider may consist merely of a knife blade disp sed below the lower end or the pipe 3!. One

- stream oi solution fiows from the dividing champasses through the jacket formed by the cylinder ll fiows through the conduit is into the conduit Is and from there into the reservoir 24 and drains back to the boiler through the conduit is connected to the conduit I. The conduit 84 may be in heat exchange relation with the conduit I! and the point or connection of the conduit 30 to the conduit It may be varied as desired to obtain the best operation 01' the system.

It will be apparent that the rectifier assembly of Figure 2 causes a transfer or heat to the strong aqua from the refrigerant gas fiowing irom the gas separation chamber through. the conduit I! to the conduit It in a way similar to that described above in connection with Figure 1. One difierence is to be noted, however, and that is that in the arrangement of Figure 2 the absorption liquid flows downwardly through the jacket ll whereas in Figure '1 it flows upwardly therethrough. The strong aqua thus flows in counterfiow to the movement of vapors through the inner cylinder II of the rectifier.

In the arrangement or Figures 1 and 2 a gas lift pump is employed for circulating the absates fiow through the conduit ll into the condenser C as in the arrangement of Figure l. The evaporator and absorber may be the same as described above in connection with Figure l and the parts which correspond are similarly designated. Absorption liquid is circulating between the boiler, the rectifier and the absorber by means oi a liquid pump diagrammatically illustrated at 40 which is adapted\ t-o be driven by an electric motor 4|. Liquid is supplied to the pump 4i] through the conduit 42 from a reservoir 43. The liquid is then lifted through the discharge conduit 44 01' the pump into the top of the absorber and it then fiows by gravity down through the absorber, then through the conduit 4! into the top the jacket 15 surrounding the rectifier cylinder ll. The bottom oi the jacket II is connected to some convenient point in the analyzer ll by means of the conduit 48. After trickling downwardly over the baflle plates 38 in the analyzer, the liquid flows through the boiler B and back to the reservoir 43 through the conduit 41. Both the conduits 45 and 48 may be in heat exchange relation with the conduit 41 as in the somewhat similar arrangement in Figure 1. The heat transfer area between these conduits may be varied as desired.

The Jacket ll may be vented into the conduit I. by means of a pipe 21 and the rectifier chamber It may be drained into the conduit 46 by means oi the small U pipe 48 connected to the lower end of the conduit 39. i

The top of the reservoir 43 should be vented by means of a conduit 49 connected to the lower end oi the inert gas conduit I8.

The operation oi! this system is similar to that described above in connection with Figure 1, the only diil'erence being in the means for circulating the absorption liquid.

In both of the arrangements of Figures 1 and 2, the jacket I! surrounding the rectifier cylinder ll is merely a plain cylinder and is maintained full 01' strong aqua. In the arrangement of Figure 5, on the other hand, the Jacket I5 is provided with a number ofbaille plates arranged in staggered relatlon'as best shown in Figure 6 and which are marked 50. The baffle plateslll aid in causing the transfer of heat from the vapors in the rectifier cylinder [3 to the aqua solution in the Jacket l5.

In the design of an absorption apparatus to include the special rectifier for permitting heat exchange between the hot vapors from the boiler and the strong aqua, the dimensions of the apparatus may be important if it is necessary to install the apparatus in a cabinet. In order to decrease the height to which the absorber must be elevated above the boiler to permit the use oi the special heat exchange rectifier described above the use of a. horizontal or slightly inclined rectifier may be employed and an arrangement of this sort is illustrated on the drawings in Figures 8 to 11 inclusive.

In the arrangement of Figure 8 a gas lift pump is employed for raising the absorption liquid as in the arrangement of Fi ure 1 and various other I parts are the same asthat in Figure 1 and are similarly designated.

a solution divider a2 is shown located below the absorber, win the arrangement oi Figure 2 and this element is similarly designated. Bolution drains from the absorber through the conduit Ii into the solution divider l2 and some flows through the conduit 34 back to the boiler while others fiow through the conduit 33 into the jacket I! around the rectifier. The solution leaves the jacket I! through the conduit 25 and flows into the reservoir 24 and from there to the conduit I8 back to the boiler, the conduit 36 Joining the conduit 34.

The rectifier shown in Figures 8, 9, l0, and 11 consists of a horizontal or slightly inclined cylinder ii provided with a number or horizontally extending baflle plates 52. The bailie plates are preferably inclined in the same angle as the cylinder ii. The trays may be supported on and held in spaced relations by means of a number of substantially vertically extending baflie plates ll arranged in staggered relation. The ballie plates which extend down to the bottom or the cylinder it may be provided with small openings 54 to allow the passage of liquid therethrough. With' this construction gas enters the cylinder 5| through the conduit I2 and passes upwardly and then downwardly over the trays II, as directed by the baille plates 53 until it leaves the cylinder 5i through the conduit ii at the left hand end thereof, as viewedin Figure 8.

The trays I! which pass horizontally, or substantially horizontally, through the baille plates II may have slots therein for permitting the liquid to flow along each tray but in the arrangement shown a substantially tight fit is illustrated so that the liquid which collects upon the trays as the result 01' the rectification (which may be called the reflux solution) drips from the upper trays on to the lower one in between each of the baflle plates 53 until it collects at the bottom 01 the vessel 5i and is drained through the holes 54 in the alternate baflle plates 53 and leaves the rectifier through the conduit 28 connected to the lower end ,of the vapor supply conduit l2.

It will be seen that with this construction a large area 0! contact for rectification is provided and at the same time a system for transferring heat to strong aqua is provided while utilizing a slight amount of vertical space.

From the above description, it will be clear that several diflerent types of rectiflers adapted to be cooled by strong aqua in accordance with the present invention have been illustrated and described. In all of these arrangements the rectifier is shown situated above the normal solution level in the reservoir 24 so that the rectifier can be drained by gravity flow into the boiler. It is of course within the purview of the invention to locate the rectifier partly, or entirely, below the normal solution level in the reservoir 24 and use a 'saoss absorption liquid between the boiler and the at sorber and a liquid heat exchanger, the combination of a rectifier and means for'transferring heat from the rectifier to absorption liquid flowing from the absorber to the boiler. the arrangement being such that the absorption liquid flowing from the absorber to the boiler passes first in heat exchange relation with solution fiowing fromthe boiler to the absorber. then in heat transfer relation with the rectifier and then again in heat exchange relation with absorption solution fiowing from the boiler to the absorber.

2. In a continuous absorption refrigerating system having a boiler. an absorber and means for circulating absorption liquid therebetween. the combination of a rectifier and means for transferring heat from the rectifier to absorption liquid, fiowing from the absorber to the boiler. both said rectifier and, said heat transfer means including balling means positioned to cause the 'fiuids within the rectifier and the absorption liquid to fiow through tortuous passageways. the arrangement ,being such that the liquid leaving the absorber flows by gravity in heat transfer relation with the rectifier and then by gravity to the boiler.

3. A rectifier assembly adapted-for use in an absorption refrigerating system. said assembly consisting of a cylindrical vessel disposed substantially in a horizontal position. a jacket surrounding said vessel, means for supplying vapors to the inner vessel and means for supplying liquid from a part of said refrigerating system to said jacket to take up heat from the vapors in said vessel, said vessel having a plurality-of substantially horizontal trays therein and a plurality of substantially vertical bailie plates in spaced. staggered relation along said trays.

4. In an absorption refrigerating apparatus. a generator including a vapor liquidlift. an absorber, a heat exchanging device, means for conducting weak absorption liquid from said generator to said absorber, means for conducting a portion of the strong absorption liquid from the abmrber'to said lift in heat exchange relation with said weak liquid, means for conducting another portion of said strong absorption liquid from the absorber to said heat exchanging device, means for conducting the liquid from the heat exchanging device to said lift and means for conducting vapor from said generator to the heat exchanging device.

5. In an absorption refrigerating apparatus. an absorber having a liquid sump, a. generator having a vapor liquid lift chamber located below the liquid level in said sump, a heat exchanging deconduit means for conducting vapor from said generator to said condenser. said solution circuit including means to conduct a portion of said strong solution into heat exchange relation out of contact with vapor fiowing from said generator to said condenser and another portion of said strong solution into heat exchange with weak solution leaving the boiler.

7. In an absorption refrigerating apparatus, a generator. a condenser, an absorber. means for fiowing weak solution from said generator to said absorber, conduit means for vapor from said generator to said condenser including a rectifier. positioned'below the liquid level in said absorber. means for fiowing strong solution from said absorber into heat exchange with said rectifier by gravity to cool said rectifier and transfer heat from vapor in said rectifier to said strong soluvice below said level and above said chamber,

means for conducting weak absorption liquid from said generator to said absorber. means for conducting a portion of the strong absorption liquid from said sump to the generator in heat exchange relation with said weak liquid. means for generator, a condenser, an absorber, a solution circuit for conducting weak solution from said enerator to said absorber and strong solution from said absorber to said generator, vapor lift means for circulating said solution in said circuit.

tion and means for fiowing'liquid condensed in said rectifier and said strong solution by gravity to said generator. said last mentioned means including means for bringing said liquid and strong solution into contact with vapor leaving the genera I. That method of separating absorbent vapor from refrigerant vapor produced in an absorption refrigerating apparatus and in pre-heating cool strong solution which comprises passing strong solution in heat exchange with hot weak solution to partially heat the strong solution. passing said vapor mixture in heat. exchange relation but out of contact with the partially heated strong solution of absorbent medium and refrigerant whereby the absorbent vapor is condensed and the heat of condensation is given up to the strong solution to liberate refrigerant vapor from said strong soiution, conducting refrigerant vapor so liberated into the refrigerant vapor from which the absorbent vapor has been removed and further heating the strong solution by heat exchange with hot weak solution. I

9. That process of exchanging heat between the fiuids of an absorption refrigerating apparatus having a generator assembly for driving off refrigerant vapor from a solution and an absorber I for reabsorbing the refrigerant vapor into the solution comprising. bringing strong cool solution from the absorber into heat exchange relationship with warm lean solution from said generator assembly in a first place of heat exchange to partially heat said strong solution. then bringing the partially heated strong solution into heat exchange with vapor from said generator assembly in a second place of heat exchange to condense solution vapor and transfer the heat of condensation to the strong solution and finally bringing the strong solution into a third place of heat ex change with hot lean solution coming directly from said generator assembly. I

10. That process of exchanging heat between the fluids of an absorption refrigerating apparatus having a generator assembly for driving off refrigerant vapor from a solution and an absorber for reabsorbing the refrigerant vapor into the solution comprising. bringing strong cool solution from the absorber into heat exchange relationship with warm lean solution from the said generator assembly in a first place of heat exchange to partially heat said strong solution, then bringing the partially heated strong solution into heat exchange with vapors from said generator. assembly in a second place of heat exchange to condense solution vapor and transfer the heat of condensation to the strong solution and finally bringing the strong solution and the condensed solution vapor into a third place of heat exchange with hot weak solution flowing directly from said generator assembly.

11. That process of exchanging heat between the fluids of an absorption refrigerator having a generator assembly for driving refrigerant vapor from a solution and an absorber for reabsorbing the vapor into the solution comprising, bringing strong solution from said absorber into heat exchangewith weak solution from said generator assembly in one place of heat exchange after the weak solution has been partially cooled in another place of heat exchange by fluids flowing to said generator assembly to partially warm said strong solution, and thereafter bringing the partially warmed strong solution into heat exchange out of contact with in a third place of heat exchange with vapors from said generator assembly to condense solution vapor and transfer the heat of condensation to the strong solution.

12. That process of exchanging heat between the fluids of an absorption refrigerating apparatus having a generator assembly for driving refrigerant vapor from a solution and an absorber for rabsorbing the refrigerant vapor into the solution comprising, bringing strong solution from said absorber into heat exchange with weak solution from said generator assembly after the weak solution has been partially cooled by fluids flowing to said generator assembly to partially warm said strong solution, thereafter bringing the partially warmed strong solution into heat exchange with vapors from said generator assembly to condense solution vapor and transfer the heat of condensation to the strong solution and merging the condensate thus formed with the strong solution flowing to said generator assembly.

13. An absorption refrigerating apparatus comprising: a generatorassembly for driving refrigerant vapor from a solution; an absorber for reabsorbing the refrigerant vapor into the solution: a closed circuit between said generator assembly and said absorber and means for circulating the mixture of refrigerant and solution through said closed circuit; said closed circuit including a three part heat exchange means between said generator assembly and said absorber; said exchange means comprising a first place of'heat exchange for bringing strong solution flowing to said generator assembly into heat exchange with weak solution flowing to said absorber to partially heat the strong solution, a second place of heat exchange for bringing the partially heated strong solution into heat exchange out of contact with vapors flowing from said generator assembly to condense solution vapors and further heat said strong solution anda third place of heat exchange for bringing the furtherheated strong solution into heat exchange with hot weak solution directly flowing from said generator assembly.

14. An absorption refrigerating system having a circuit for absorption liquid including an absorber having a surface level of liquid therein. a generator vapor lift assembly having a surface l level of liquid therein above that in said absorbe and heat exchange means, said exchange means being connected to conduct vapors and liquid from the generator and liquid flowing to the generator in heat transfer relation out of physical contact with each other, said exchange means also being located at a level below the said surface level of liquid in said absorber, and means for creating portion of said heat exchange means into said liquid circuit.

15. An absorption refrigerating apparatus comprising, an absorber having a surface level of liquid therein, a generator vapor lift assembly having a surface level of liquid therein above that in said absorber, a condenser, a triple pass heat exchange means, means for conducting vapor from said generator vapor lift assembly through one pass of said heat exchange means to said condenser, an absorption liquid circuit including means for conducting. weak absorption liquid from said generator vapor lift assembly through ,a second pass of said heat exchange means to said absorber and means for conducting strong absorption liquid from said absorber through the third pass of said heat exchange means to said generator vapor lift assembly in heat exchange relationship withvapor flowing through said one pass, said exchange means bein located at a level below the said surf-ace level of liquid in said ab-' sorbet, said circuit including means between said heat exchange means and said generator vapor 3;; lift assembly for creating a third surface level below at least a portion of said heat exchange means for permitting drainage of condensate from the vapor pass of said heat exchanger to said circuit.

- CURTIS C. COONS.

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